Daniel Alvarez woke up Thursday on a spoil island south of the Belleair Causeway and folded the tarp under which he had slept through pouring rain the night before. The clouds had parted for the morning sun, but he knew there would be storms ahead, so he wanted to get an early start.

He pulled his black hat down on his forehead and tucked the tarp into his 17-foot yellow sea kayak, the vessel that carried him here from Northwest Angle, Minn., the northernmost point in the lower 48, a journey of more than 3,000 miles.

He appeared healthy and unbelievably happy for a 31-year-old man who had been on a mostly solitary journey through the heart of America for eight long months, since June 11, when he shoved off for the southernmost point, Key West. He smiled big through a scraggly beard when he saw dolphins break the surface nearby.

"Cool," he said, pointing. "Dolphins."

Surrounding him, in stark contrast to his bare-bones existence, were the million-dollar homes of one of the wealthiest ZIP codes in the Tampa Bay area.

"I basically have this boat and a couple of boxes of stuff at my dad's house," he said. "The less things you have, the more free you are to move. It's great to have things, but they tend to anchor you down."

This has been his daily routine for the better part of eight months, a journey that has taken him through the Boundary Waters, Lake Superior, the Mississippi River and the Gulf of Mexico. He's not sure whether anyone has made this exact trip before and an earnest search by your correspondent couldn't turn up any record of one previous.

When Alvarez began thinking about the trip, he planned to walk; he has hiked the entire length of the Appalachian Trail, the Pacific Crest Trail and Continental Divide Trail. But when he noticed that the best route ran alongside water most of the way, he decided to try floating, despite his lack of experience in a kayak. At spots where he couldn't paddle, or where he had to switch waters, he dragged his vessel by hand alongside roads or over forgotten portages.

He carries a tent and supplies and the technology to update his blog and Facebook page, to keep those he has met along the way apprised of his progress. He has made many friends, folks changed by their encounters with him.

"He's one of those people who you remember all of your life," said Ken Larson, 61, of Two Harbors, Minn., who met Alvarez on Lake Superior. "He's a unique man. Nothing's going to grow under his feet."

"Daniel has a very big heart," said Giulia Good Stefani, 33, a lawyer in California who met Alvarez in law school at Yale and has remained his close friend. "These journeys sound so solitary, but they're a way for him to connect to people."

"He left a great impression on my entire family," said Marjorie Campagna, 44, who heard about Alvarez's trip on National Public Radio and spontaneously invited him to be her guest. Alvarez reached her home in Memphis in time for Thanksgiving dinner. They ate fried turkey, onion pie and chocolate covered bacon, and Campagna's 10-year-old son, Joseph, was awed by Alvarez. She gets choked up when she talks about it.

"What I feel like my son saw in Daniel is, you can make a way in your life to do what you love," she said. "Success is not based on the traditional things like a corner office and money in the bank."

She said Alvarez was constantly smiling during his visit, which stretched for several days.

"My son said, 'Mom, I think he's so happy because he's doing what he wants to do,' " she said.

He shoved off Thursday morning with that same permanent smile. He told stories about spooking a bobcat on the Savanna Portage in Minnesota, watching a wolf swim across the Pigeon River near the Canadian border and paddling for a solid 24 hours on the Mississippi, covering 100 miles and prompting vivid hallucinations. Early on, he found a plastic pink flamingo washed up on the bank of Lake Superior.

"I was going to throw it away in Duluth," he said. "Then I named him Frank, and once you name something … "

Frank now rides strapped to the kayak, and the two have some wild conversations.

He left the water briefly last year and hitchhiked to South Bend, Ind., to watch his father, former University of Florida great Carlos "the Cuban Comet" Alvarez, get inducted into the College Football Hall of Fame.

"We all have certain passions," Carlos Alvarez said on the phone. "Some people love art or play the piano. Daniel has a passion for adventure."

You can trace Alvarez's lust for adventure to a vacation at age 11. His mother, Anna Lee, 59, said he was having a difficult time in junior high so she offered to homeschool him for one year. They went from their home in Tallahassee to the Grand Canyon for a lesson in geology, and Anna Lee got a backpacking permit. She pulled up to the northern edge of the canyon and pointed to their destination in the distance, a few days of walking away. The boy was daunted.

"He said, 'I'm not going,' " his mother recalled. She gave him the car keys, a canteen and some money and said she would be back in five days.

"I was perfectly serious," she said. "I was going."

Soon enough, Alvarez was walking beside her.

His wanderlust was born.

"He's clearly affected by nature in a way most people aren't," said Eric Eggers, 31, a high school friend who accompanied Alvarez on two cross country road trips. "Everything Daniel does, Daniel invests in wholeheartedly."

"He just gets a creative idea in his head and goes," said Anna Lee.

During his last semester in law school at Yale, Alvarez bailed to hike the Pacific Crest Trail, then made it back in time for finals. After school, he bored quickly with corporate law.

"I got turned off on the whole idea of law," he said, surging down the Intracoastal Waterway, past Coquina Cove, the Glades and Egret Woods. "I'm the least accomplished Yale law school graduate. My classmates are all saving the world. I'm just paddling it."

This most recent back-of-the-napkin trip doesn't surprise his mother, who made him promise not to swim in the Mississippi but doesn't worry much otherwise.

"You can drive out on the highway and get hit any time, easily," she said. "I'd rather for myself to be out on an adventure. He's enjoying life to the fullest."

The cost of this trip was covered by a $10,000 prize from Outside magazine. He donated $2,000 of the prize money to charity. He's also involved with several environmental organizations that aim to protect waterways.

Alvarez likes the idea that he might inspire others to strike out.

"There's always a thousand reasons why you shouldn't take off," he said as rain started to fall. "Just go."

He and Frank plan to reach Key West in a few more weeks. Then?

"I have no idea," he said. That seems about right. He left a Times reporter and photographer on a dock near the Tom Stuart Causeway and disappeared into the driving Florida rain.

Ben Montgomery can be reached at bmontgomery@tampabay.com or at (727) 893-8650. Twitter: @gangrey.